/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.sun.org.apache.xml.internal.security.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.SecurityPermission;

/**
 * A collection of different, general-purpose methods for JAVA-specific things
 *
 * @author Christian Geuer-Pollmann
 */
public class JavaUtils {

  /**
   * {@link org.apache.commons.logging} logging facility
   */
  private static java.util.logging.Logger log =
      java.util.logging.Logger.getLogger(JavaUtils.class.getName());

  private static final SecurityPermission REGISTER_PERMISSION =
      new SecurityPermission(
          "com.sun.org.apache.xml.internal.security.register");

  private JavaUtils() {
    // we don't allow instantiation
  }

  /**
   * Method getBytesFromFile
   *
   * @return the bytes read from the file
   */
  public static byte[] getBytesFromFile(String fileName)
      throws FileNotFoundException, IOException {

    byte refBytes[] = null;

    FileInputStream fisRef = null;
    UnsyncByteArrayOutputStream baos = null;
    try {
      fisRef = new FileInputStream(fileName);
      baos = new UnsyncByteArrayOutputStream();
      byte buf[] = new byte[1024];
      int len;

      while ((len = fisRef.read(buf)) > 0) {
        baos.write(buf, 0, len);
      }

      refBytes = baos.toByteArray();
    } finally {
      if (baos != null) {
        baos.close();
      }
      if (fisRef != null) {
        fisRef.close();
      }
    }

    return refBytes;
  }

  /**
   * Method writeBytesToFilename
   */
  public static void writeBytesToFilename(String filename, byte[] bytes) {
    FileOutputStream fos = null;
    try {
      if (filename != null && bytes != null) {
        File f = new File(filename);

        fos = new FileOutputStream(f);

        fos.write(bytes);
        fos.close();
      } else {
        if (log.isLoggable(java.util.logging.Level.FINE)) {
          log.log(java.util.logging.Level.FINE, "writeBytesToFilename got null byte[] pointed");
        }
      }
    } catch (IOException ex) {
      if (fos != null) {
        try {
          fos.close();
        } catch (IOException ioe) {
          if (log.isLoggable(java.util.logging.Level.FINE)) {
            log.log(java.util.logging.Level.FINE, ioe.getMessage(), ioe);
          }
        }
      }
    }
  }

  /**
   * This method reads all bytes from the given InputStream till EOF and
   * returns them as a byte array.
   *
   * @return the bytes read from the stream
   */
  public static byte[] getBytesFromStream(InputStream inputStream) throws IOException {
    UnsyncByteArrayOutputStream baos = null;

    byte[] retBytes = null;
    try {
      baos = new UnsyncByteArrayOutputStream();
      byte buf[] = new byte[4 * 1024];
      int len;

      while ((len = inputStream.read(buf)) > 0) {
        baos.write(buf, 0, len);
      }
      retBytes = baos.toByteArray();
    } finally {
      baos.close();
    }

    return retBytes;
  }

  /**
   * Throws a {@code SecurityException} if a security manager is installed
   * and the caller is not allowed to register an implementation of an
   * algorithm, transform, or other security sensitive XML Signature function.
   *
   * @throws SecurityException if a security manager is installed and the caller has not been
   * granted the {@literal "com.sun.org.apache.xml.internal.security.register"} {@code
   * SecurityPermission}
   */
  public static void checkRegisterPermission() {
    SecurityManager sm = System.getSecurityManager();
    if (sm != null) {
      sm.checkPermission(REGISTER_PERMISSION);
    }
  }
}
